Aeronautical propeller



June 5, 1928 1,672,341-

s. A. REED AERONAUTICAL PROPELLER Original Filed June 22, 1922 4 Figs. 1 and 2, with a Patented June 5, 1928.

UNITED STATES PATENT OFFICE.

SYLVANUS A. Br m), on NEW YORK, N. Y., essrenoa in min. REED rnornntnn 00.,

INC; 0] NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AEBONAUTICAL PBOPELLER.

Original application filed June 22, 1922, Serial December 2, 1924.

.This invention relates generally to propellers for aeronautical use and particularly to propellers of the metal type, includm such as those which I' have described an I claimed-in my U. S. Letters Patent No. 1,463,556, dated July 31, 1923, and also in my a plication for patent, Serial No. 57 0,-

139, filed June 22, 1922, and. this application is a division of said application Serial No.

.. 1 570,139, which issued as Patent No. 1,518,-

- 410, on Dec. 9,1924. 0

A general object of the invention 1s to provide a metal ropeller structure wh ch can be mounted in driving relation with the drive-shaft, without weakening the pro- -peller' structure. Another objectiof the nvention is to provide mounting neans with increased resisting strength against the stress of the propeller in its operation. The invention also includes means for mounting the propeller in abutting relation to the end of the drive-shaft, so 'thatthe weakening effect of a shaft-recelving orifice in the propeller structure is avoided. There are other'important advantages result ng from the use of my improvements, which will appear from the description hereinafter given.

Certain forms of my improved propeller and certain preferred methods of constructing the same are hereinafter 'described and set forth and illustrated in,the drawings, wherein Figure 1, is a broadside view of ametal propeller embodying one form of my invention.

Figure 2, shows the same propeller as that in Fig. 1, with the view at right-angles thereto, and the propeller mounted on the end 40 of a drive-shaft projecting from a fuselage. Figure 3, shows a modified form of the propeller andthe mountin means which is spaced away slightly therefrom.

Figure 4,-shows a propeller like that in modified form of mounting means for the drive-shaft.

Figure 5, is a cross-sectional view of they No. 570,139. Divided and this application filed Serlatli'o. 753,483.

mounting means shown in Fig. 4, and shows the drive-shaft fuselage in side view.

Referring to the drawings, in the various forms herein shown, the shaft attaching means is such that I am able to dispense with the central orifice in the propeller for the reception of the shaft, and in Figs. 4 and 5, the structure is one in which there are no bolt-holes in the propeller which thus remains intact and without any openings therein.

In Figs. 1, 2, 4 and 5, I show a construction of the propeller in which a virtual 0 twist in the central part 7-8, for bringing the sections at those points to the required angle with the plane of rotation, which is accomplished by a compound bend at 18 19, and 2021, these bends being in opposite' directions and at angles 18 with 19, and 20 with 21, and each extending entirely across the propeller and the pair 18-19, being symmetrical with the pair 2021. There are various combinations of bends that will accomplish the same purpose, but I prefer that substantially of the type illustrated, wherein the plate-like character of the central part 22, affords a wide surface which will accommodate the wide face of the attaching flange, and which is especially .convenient and etficient for securing the propeller in operative position to its seat or attachlng flange. In this form, the portion of the blades 75, and 8.6, has the same twist, contour, edges and dimensions as in the other form, and there is likewise preferably a continuation of the leading edge of each blade with the trailing edge of the other.

In Figs. 1 and 2, the central flat section. 22, of the'propeller, is provided with acentrally located circular row of bolt-holes 27, and isengaged upon one side by the flat surface of a solid flange 28, which is inte- 90 .gral with the drive-shaft 11, shown as projecting from the end of the fuselage 29'. This attaching flange 28, is a solid metal disk except for a circular row of bolt-holes,

fOIi'ned therein in correspondence with those of the propeller indicated at 27, for the reception of the attaching bolts 31, which pass through the two parts and hold them in fixed relation.

In Fig. 3, substantially the same structure is shown as that in Figs. 1 and 2, except that the propeller has the helical central section, instead of the flat section 22, and the solid attaching flange 32, which is integral with the drive-shaft 11, is shaped or bent to conform to the curved surface of the central. portion of the propeller with which it makes close contact, the bolts 33, being employed to unite the parts as shown.

' In Figs. 4; and 5, the drive-shaft is pro vided at its ends with an integral attaching flange or head-34, formed of a "solid piece of metal with its outer face provided with a transverse seat or depression in which is snugly fitted the flat central section 22, of the propeller, which is securely held therein by -means of a transverse clamping member or bar 36, .which'is detachably secured to the head or flange 34,by means of bolts 37.

As the propeller is securely seated betweenv the ribs or sides of the depression, thelatter serve as abutments for receiving the stressof the propeller when rotated.

It is evident that in none of the arrange ments described herein, is the attaching 7 means required to reinforce the twist or bend in-the propeller, but functions merely as an attaching means to the drive-shaft embracing the latter over sufficient distance to allow adequate attachment. The twist or bend of the metal or other material imparted during manufacture of the propeller,-for the -pur- 'pose of iving the blades the appropriate.

inner or ub anglesnecessary for helical or similar twist, perpetuates itself during all the stresses of protracted-operation in flying,

" solely by its inherent elastic rigidity or set,

at the angles, bendsfor curves imparted-dun ing manufacture or intentional adjustment. In order that such constancy of shape under stress may exist there must be a relation be-- tween the thickness andthewidth of the material and its elastic limit and other physical properties to insure constancy at the rate of rotation, thrust 'and'other conditions specified by the particular flight duty forwhich.

the propeller is planned. By my construction of the entire propeller from' a. plate which need not exceed one inch in thickness, at the thickestpart, I am able to obtain effective thrust at. points comparatively close to the axisof rotation, say for example, nine u :add.

or twelve inches-therefrom, and I t materially to the aggregate efficiency 0 propellers' In the form of my propeller in which the centralblade connecting portion is made fiat and without bends or twists therein, as indipeller is bolted through a series of small.

openings. In another form the propeller is clamped between holding plates that are connected at the margins of the propeller, which is left wholly -imperfora'te so that its maximum strengthis retained. While the constructions referred to produce a continuation of the leading edge of one blade with the trailing edge of the other the invention is not limited to this relation of parts.

I wish to be understood as not limiting my invention to the particular forms herein shown and described, as it is manifest that various modifications may be made in the different parts, without, however, departing from the spirit of my invention.

'of rotation, and central abutting drive-shaft attaching means having said blade-connecting part countersunk and secured therein.

2, In aeronautical propeller construction, a substantially flat central attaching part Having thus describedniy invention, what having suitably bent metal blades attached thereto, a drive-shaft, connecting means he tween said attaching part and said shaft and comprising lateral abutments for engaging the edges of said attaching part.

1 3. In aeronautical propeller construction, a substantially flat central attaching part having suitably formed blades attachedthereto, a drive-shaft, connecting means between said attachin part and said driveshaft and comprising lateral abutments against which theedges .of said part bears, and a holding member for securing said part in fixed relation with the connecting means.

4. In aeronautical propeller constructidn,

said propeller having a central blade-con-v necting part formed plate-like and imperforate at the axis of rotation, and drive-shaft attaching means comprising a member provided with a wide face for engaging said plate-like portion ofv said central part and having oppositely arranged marginal abutments' engaging the edges of said central part, and means for securing said part to said member.- 1 f 5. In'aeronautical propeller construction,

a single-piecepropeller made from a relatively thin plate of metal with blades having their outer portions tapering in width an thicknessto the ti sand with an imperforate central. part at t e axis of rotation, driveshaft attachlng means having an abutting end-flange to which the central part of said drive-shaft attachin means having an abutpropeller is attachedface-on. I ting end-flange to w ich the central part of 10 6. In aeronautical propeller construction, said propeller is attached faee-on, said abuta single-piece propeller made from a relatin flange having upset parts embracing tively thin plate of metal with blades havsai central-part of the propeller, and a ing their outer portions-ta eri'ng in width hdlding-member'attached to the upset parts and thickness to the tips an with an imperfor securing the propeller to said flange. Y

fbrate central part at the axis of rotation, SYLVANUS A. REED. 

